Low Cost Material for Hot Water HX

[MarkShark]

I am trying to find a low cost (~$20USD/m2) material that is capable of surviving ~10years in an oxygenated hot water environment (70degC) with the material also able to survive occasional exposure to 140degC temperatures. i.e. An unpressurised solar collector application.

Material thickness isn't too critical (the HE is unpressurised) as long as it can span 1m horizontal distances, so something like a stainless steel/titanium foil would be sufficient.

Hot Water contact is in the form of a uniform 200um layer across the surface.

Requirement summary:
R-Value through thickness < 0.0005 K.m2/W (quite relaxed T conductivity requirement)
Cost < 20USD/m2 (>1000m2 qty)
Weight < 5kg/m2
Twater > 70degC
Tmax > 140degC

Any ideas on the following:
Ceramics, SS/Titanium/Cu metal foils, Aluminium with coating or galvanic protection (passive forced), commercially available polymer,.

Please include the material grade, costs and where I can obtain this material from.

Thanks sincerely
Mark

 

[joeswoes]

You're missing some info..

What flexure (sag) is allowed along the 1M of unsupported span ?

What is the shape of the item ?

Do you want a more conductive or more resistive material ?

 

[MarkShark]

Basically this is for a glazed solar FLAT plate collector inclined at 45degrees.
Sag <10mm over 1m span. Can be held in tension.
R-value < 0.0005 I.e. I want more conductive than this.

 

[EdStainless]

Try looking at 439 stainless. It handles hot water well and is lower priced than 304.

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